Method of making sliders



Sept. 8, 1931- G. E. PRENTICE I METHOD OF MAKING SLIDERS Filed June s. 192

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Patented Sept. 8, 1931 I UNITED STATES.

GEORGE nrnnnrrcn, or BERLIN, ooNNEc'rIour" METHOD OF MAKING SLIDERS Application filed June 29,

This invention pertains to separable fasteners of that type of whicha good example is disclosed'in the patent to Prentice and Legat, No. 1,658,392 dated February 7, 1928 and relates more particularly to a process or method of making an improved slider.

The usual form of slider employed in such fasteners comprisesspaced substantially parallel front and rear wings or plates united H) at or near one end by a relatively narrow connecting portion or neck, the innerops posed surfaces .of the wingshaving cam-like members which, in cooperation with certain elements associated with the connecting memher or neck, define guides for the opposed series of fastener elements. The successful operation of such a slider isdependent upon the maintenance ofthe wings'in accurately spaced relationship, but as the wings are united at or near one end only and as the slider is subjected to severe stresses tending to spread the wings apart, difiiculty has been experienced in making a slider sufficiently rigid without making it unduly heavy and cumbersome.

Various modes of making such sliders have heretofore been propojsed; For example, attempts have beeri in ade to produce them by drop forging or die casting, but such methods are expensive and from the nature of the operation, the resultant sliders are heavy, cumbersome, rough, and generally unsatis-, factory. A more common and fairly successful method consists in making the slider of sheet metal by punching and bending operations, but since sheet metal bends so easily, it is, usually necessary to reinforce a sheet metal slider by means of-rivets, external yoke pieccs. ribs or the like, requiring several successive operations in the manufacture of such a slider, thereby increasing the cost of production, while the finished slider often presents a clumsy, angular, and unpleasing appearance. In one proposed modification of the sheet metal slider, the metal at the neck of the blank is swaged to provide a heavy projecting rib. and when the blank is bent this rib, which is disposed at the inner side of the bend, provides extra thickness designed to give greater stiffness at 1928. Serial No. 289,288.

faces, and as the fibers of the thick metal are heavily stressed and distorted in bendin '55 this arrangement in reality afi'ords little, 1f any, more resistance to separation of the wings than does the'ordinary unreinforced sheet metal slider. Moreover, in such con-' struction, even more than i-n other usualt es of slider, the inner surface of the neo is irregular, rough and varies in configuration in different sliders, and as this inner surface of the neck acts like a-i eam in performing the important function of guiding the opposed series of fastener elements as they ap: proach and recede, the slider so constructed often fails to work with the desired ease and smoothness.

In accordance with the present invention I provide a slider possessing the inherent stiffness and strength which results from integral homogeneous construction and which works with the greatest ease and smoothness, but which is. markedly different from other integral constructions produced by die casting or, the like operations in that it is light in weight, of small dimensions and of pleasing appearance. The new slider also represents a distinct advance over usual sheet metal constructions in its neatness, freedom from external stifi'ener yokes or ribs, low cost of production and small size.) This slider ma be used with fasteners of the kind in w ich each series of fastener elements consists of independent members attached to a flexible stringer, as illustrated for example in my aforesaid patent,--or of the general type de scribed in my Patent No. 1,562,253, November 17, 1925 in which the fastener elements of each series form portions of a continuous length of wire.

In accordance with this invention I produce the slider from a solid metal blank of proper dimensions by a mechanical process or method in which the principal parts of the slider body. result solely from cutting so that the normal fibrous structure of the metal is not disturbed or unduly stressed, and although certain minor features require bending or similar operations,- no substantial weakening of the slider body results therefrom. All of the various steps in the proacter capable of performing its intended function with the highest ease and efficiency, and

exhibiting surprising strength and rigidity as compared with sliders formed by swedg- Legat No. 1,658,392 above referred to, but

ing and bending sheet material.

In the accompanying drawings, I have illustrated one desirable embodiment of the present invention, by way of example, and have shown certain desirable steps in apreferred method of producing the improved slider, but wish it to be understood that thespecific construction here illustrated and the several steps'and the order of steps here disclosed are by way of example only and are not to be regarded as limiting the scope of the invention.

In the drawings,

Fig. 1 is a fragmentary front elevation, to

large scale, showing a fastener of the gen-' eral type above referred to, provided with a slider constructed in accordance with the present invention;

Fig. 2 is a composite view showing in front elevation and in edge elevation, respectively, a blank of a desirable shape for use in constructing the improved slider:

Fig. 3 is a composite view showing in front elevation and in edge elevation, respectively, the appearance of the blank after it has been subjected to a suitable operation for producing a projection on its forward face adapted, at a later stage, to constitute a retainer for a pull device;

Fig. 1 is an edge elevation of the blank at the end of the cutting operation which results in the formation of the front and rear wings of the slider;

Fig. 5 is a vertical section on the line 5-5 of Fig. 4.;

Fig. 6 is a front elevation of apull device of a type which may conveniently be assembled with the slider body herein disclosed;

Fig. 7 is an edge elevation of the complete slider, showing the inturned guide flanges at the edges of the front and rear wings and showing the pull device (in section) as attached to the retaining member on the front wing; v

Fig. 8 is a vertical section on the line 8-8 of Fig. 7;

Fig. 9 is a plan view of the slider shown irii Fig. 7. but omitting the pull device;

Fig.10 is a bottom plan view of the slider of Fig. 7. omitting the pull device;

Fig. 11 is a vertical section on the line 111l of Fig.8:

Fig. 12 is a fragmentary edge elevation similar to Fig. 4 but showing a modification;

formed from the desired material.

Fig. 13 is a view similar to Fig. 12 but showing a further modification; and

Fig. 14 is a horizontal section on the line 1414 of Fig. 13.

In Fig. 1 of the drawings the numerals 1 and 2 designate a pair of flexible stringers or tapes of the usual kind to whose opposed edges the series 3 and 4 respectively of fastener elements are secured. As here shown, these fastener elements are of the type more fully disclosed in the patent to Prentice and while this particular form of fastener is here illustrated, it is to be understood that the improved slider forming the immediate subject matter of the presen application is applicable to other types of fastener as well as to that here specifically shown.

In the production of the improved slider, I first prepare a blank 6 from the material to be employed, (usually, although not necessarily metal) having roughly the outline and dimensions of the finished slider body. This blank may be cut, punched, or otherwise As indicated in Fig. 2, the blank is of more or less keystone contour, comprising the top face 7, the bottom face 8, the lower lateral edge surfaces 9 and 10, and the upper edge surfaces 11 and 12. In accordance with one desirable mode of procedure, this initial blank is made somewhat thicker in a front to rear direction than the desired slider body and is next subjected to pressure in suitable dies whereby it is somewhat thinned and expanded laterally and reduced substantially to the final external size and contour of the finished slider body. At the same time,'I prefer to form an integral projection on one face of the slider, preferably the front face, which later forms an anchorage for the pull device as hereafter described. In Fig. 3, I have shown the result of this shaping operation, it being noted that the lower face 8. of the blank has become longer than in Fig. 2 and that the edge faces 9- and 10 have taken an arcuate concave curvature. In Fig. 8 the projection 13 formed in this operation is shown as extending from the top 7 to the bottom 8 of the slider body. \Vhile it is desirable to proceed as above described since the compression of the metal in thus shaping it adds to its density and homogeneity, I contemplate that if desired the original blank may be made of the proper thickness, lateral dimensions and contour to correspond to the finished slider body and that other means than the projection 13 might then be employed for attaching the pull device.

In whatever manner the final blank of Fig. 3 be formed, it is now subjected to a cutting I operation whereby material from the interior of the blank is removed, leaving a slot 14 intermediate the front and rear portions 15 and 16 which now constitute the front and rear wings of the slider. Preferably this slot 14 isproduced by a milling. operation which leaves the front andrear faces of the blank intact and which makes the opposed inner faces of the wings 15 and-lfiesrnooth and accurately parallel. This slotla extends in this art, is of: substantially triangular shape. As. shown in Fig. 5 the upper face 7 of this neck preferably coincides with the upper surface 7 of the blank, while the converging sides 18and19 -ofthis neck member meet at a point 20 substantially below the surface 7? and-preferably about midway between the top and bottom surfaces 7 and 8 of the slider, body. Preferably, the edge faces 18 and19. of this neck member are concavely curved upon arcs-more orless concentric with the curved edges 9 and 10 of the body. If the slot 14 be producedby a milling these curved surfaces 18 and 19 operation, may well represent the curvature ofthe-edge of the milling. cutter. These surfaces are smooth, uninterrupted, and without abrupt changes in shape, and are eminently well adapted to perform. the function of guides for the opposed seriesoffastener elements.

In thus forming the slot 14 by a. cutting operation, the-metal of'theslider body is not distorted or subjected to injurious stress, and the fiber of the metal in the neck portion 17 remains undisturbed: and retains all of its original strength and ability to resist deformation. Referring to Fig 11, it may be noted that the post or neck 17 is of. homogeneous composition, wholly without folds, seams, sutures or the like, and thus through: out its entire depth possesses the inherent and original strength of the metal of the blank. This neck member17. extending as it does downwardly from the upper surface of the slider body to a point substantially midway the length of the slider body, affords adequate resistance to separation ofthe front and rear wings, strengthening rib extcndingaround the neck portion. of the slider is necessary. The external dimensions of the slider body are thus kept at a minimum. least of the slider body is wholly free from any projection, while the neck portion is also free of any projecting riband is preferably flush with the upper surface of the slider body.

The next step in the operation preferably consists. in bending the lateral edge portions such block forming. a part of blank and being integrally Preferably the so that no external yoke or The rear wing 16 at of one or both of the wings inwardly to form guide flanges. and 24. lV-hile I have here shown both the front andrcar wings asprovided with suchguide flanges, I contemplate that-when the slider is to be .used;with certain types of fastener element, it will not be necessary to provide lateral guide flanges upon .but one. ofthe wings.

Referring to. .Fig. 8. "t, may the depth of the neckliis such that itcxtends well below the upper ends of the lateral flanges23 and 24, thereby forming clearly defined guide channels 25 and 26 of. substantial length and unifornrwidth at the upper end of the slider body,- s uch channels incrginginto a single channel-"27 at the lower. partof the slider body. These channels are of accurate dimensions and have smooth and. uniforindeiining.walls andby reason of the substantial length of the upper channels-25 and 26 accurate, smooth, and easy interengagemcnt, of the opposed,- fastencr. elements is assured.

At someconvenient point in theopcration, either before or after the formation of the be noted, that,

lateralifianges 23 and 24,-1 subject the projection 13 to a suitable operation or operations to adapt it for thereception of a pull: des vicc. As shown in Fign'i'the projection has been piercedtransversely to provide the clongate slot :38, leayiug only the outer portion of the projection to foim anelongate loop 13 integrally united at itsuppcr and lower ends to the front'wing-of. the slider body. Tothis loop I attach a suitable pull device which, may, for example. be of the type shown in Fig. (5. This pull dcviceconipriscs a piece of sheet material 29 cut to proper shape and having. an opening 230 into which lcads a slit 31 defining spaced pivot cars 32 and 33. In assemblingthe pull with the slider body the cars 32 and 33 may be sprung or bent apart sufficiently to enable them to be entered'into the slot 28, whereupon they are returned to their original position, thus forming pivoting elements for securing the pull to the loop 3; In order to imparta pleasing appearance, the exposed surfaces of the slider may. if desired, be polished, plated, enameled, or otherwise finished appropriately to-the use to which it is to be put.,

The slider thus completed may be assembled withany desired form of fastener of the general type referred to and by reason of the accuracy of finish of its interior surface is found to operate. much more smoothly and eas ly than any previously known form of slider. At the same time this improved slider is extren'icly rigid; it is very small: of minimum front'to rcar thickness; and of neat and pleasing appearance.

\Yhilc the arrangement shown in Fig. 7 is desirable in proi 'iding zm elongate loop 13', which permits the pull to bc positioned either at the top or bottom of the slider, I conwing is of the same length, as shown in Fig.

3. but whereinthe projection is not perforated through its entire thickness, as shown in Fig. -7, butmerely recessed at its 0ppo-.

site sides as shown at 28 providing socket slots for the'pivotelements of the pull de vice. the outer'member 13 of the pro ection remaining of its original transverse thick-,

ness.

-VVhile I prefer to provide integral means for attaching the pull device, as above describedyI contemplate that the pull device may be secured by soldering or brazing directly or indirectly to the body of the slider at any desired point or may be attachedin any other manner familiar to those skilled in the art.

\Vhile I have herein illustratedand described a certain desired order of steps useful in producing my improved slider, I wish it to be understood that this order of steps isnot wholly essential but that the .order may be varied and that it is within the scope of the invention to introduce other steps or, as above suggested, to omit certain of the stepshere disclosed without departing from the spirit of the invention. Neither is it essential that the external contour of-the slider body met the blank from which it is made be in exact accordance with the present disclosure, or that the original blank be produced'by cutting or punching from solid stoekalt-hough this method is preferred. lVhile metal is preferred inmost instances as the material from which this slider is made, I contemplate that other materials may be found useful for the purpose, and I regard the present method as applicable to' the making of sliders from-such other materials and wish it to be understood that the l. Thatniethod of making sliders for use in separable fasteners of the. class described which comprises as steps preparing a blank roughly approxin'iating the desired slider in shape and size, and cutting away the material of the blank to leave spaced front and rear wings having smooth innersurfaces and a substantially triangular neck integrally uniting the wings adjacent to one end, the neck having smoothly curved lateral surfaces converging toward the other end of the sli der.

2. That method of making sliders of the class described which comprises as steps preparing a blank, slotting the blank to provide front and rear wings integrally united at one end, and turning in the lateral margins of one at; least of the wings to provide guide flanges.

3. That method of making sliders of the class described which comprises as steps preparing a blank roughly approximating the desired slider in shape and size, providing a projection on the front face of the blank, removing material from the interior of the blank to provide front and rear wings integrally united adjacent to one end, providing the projection with a socket, and pivotally mounting a pull device in said socket.

4. That method of making sliders of the class described which comprises as steps preparing a blank roughlyapproximating the desired slider in shape and size, forming a projection on its front face, removing material f'rom the interior of the blank to provide front and rear wings integrally united adjacent to one end, shaping the material of said projection to provide an elongate retainer integrally united to the front wing, and attaching a pull device to said retainer.

5. That method of making sliders of the class described which comprises as steps preparing a blank roughly approximating the desired slider in shape and size, removing material from the interior of the blank to provide front and rear wings integrally united adjacent to one end, providing an elongate loop integrally united at one end at least to the slider body, and attaching a pull device to said loop.

Signed by meat Berlin, Connecticut, this twentysiith day of June 1928.

GEORGE E. PRENTICE. 

